FIRST RECORD OF A CHIMAEROID FISH FROM THE EOCENE OF THE SOUTHEASTERN UNITED STATES

Abstract

Although fossilized teeth of sharks and rays are common elements in Eocene nearshore marine sediments of the southeastern United States (Parmley and Cicimurri, 2003 and references within), fossil remains of chimaeroid fishes are unknown from this region. Here we provide the first report of an Eocene chimaeroid fish from the southeastern United States, consisting of a partial, well-preserved left mandibular tooth plate recovered from central Georgia. The specimen was collected from late Eocene (ca. 36.0–34.2 Ma; Parmley and Holman, 2003) Clinchfield Formation sediments exposed in an abandoned central Georgia kaolin mine formally known as the Hardie Mine (Westgate, 2001). The Hardie Mine is located approximately 3.9 km north-northeast of Gordon, Wilkinson County, Georgia. This site has yielded a relatively well-preserved and diverse nearshore marine vertebrate fauna consisting of sharks, rays, bony fishes, reptiles, and whales (Westgate, 2001; Parmley and Cicimurri, 2003; Parmley and Holman, 2003). Additionally, the vertebra of a colubrid snake (Parmley and Holman, 2003) and partial teeth of at least two species of land mammals (unstudied fossils in the paleontological collections of Georgia College and State University–GCVP) are known from the Hardie Mine site. The vast majority of fossils collected from the Hardie Mine were recovered from a series of spoil pile sediments. It has been shown, however, that these sediments were derived locally from nearby in situ fossiliferous Clinchfield Formation sediments exposed in the north wall of the mine (see Westgate, 2001; Parmley and Cicimurri, 2003; Parmley and Holman, 2003). For the purposes of this report we follow the descriptive terminology utilized by Stahl (1999), and a comprehensive classification scheme can be found in Stahl and Parris (2004). We utilized the histological terminology of Stahl (1999), but we did not perform any direct microscopic analyses of tissues. The specimen …